Phase 3 trial of arbaclofen placarbil (AP) for the treatment of spasticity in multiple sclerosis (MS)

XenoPort announced that it plans to move arbaclofen placarbil (AP), also known as XP19986, into Phase 3 development as a potential treatment of spasticity in multiple sclerosis (MS) patients. This trial will be a multi-center, randomized, double-blind, placebo-controlled study designed to assess the efficacy and safety of AP as a treatment for spasticity in MS patients. Patients who complete this study would have the option to enter a long-term study to evaluate the safety of AP in MS patients. Following successful outcomes from these studies, XenoPort would file an NDA with the FDA using the 505(b)(2) application process.

AP is a patented new chemical entity that is a Transported Prodrug of R-baclofen designed to engage natural nutrient transport mechanisms found on intestinal cell membranes, thereby gaining efficient entrance into the bloodstream. AP is then rapidly converted by high-capacity enzymes to the parent compound and natural substances with favorable safety characteristics. R-baclofen is an agonist of the target known as gamma amino-butyric acid(B), or GABA(B), receptor.